1. Field of the Invention
The present invention relates to a communication device that provides proximal communications in wide band, and a system including the same.
2. Description of the Related Art
A communication sheet that includes a plurality of proximal coupling portions and a plurality of relay communication circuits arranged on the surface of the sheet wherein each relay communication circuit forms a communication network with the proximal coupling portions and other relay communication circuits, has been proposed.
The communication sheet data communicates with other communication sheets via the proximal coupling portions when the communication sheet touches or comes closer to other communication sheets. The communication sheet like this has been proposed in order to form a wireless communication network such as wireless LAN (Local Area Network).    [Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-19979
Since the communication sheet described above forms a communication network with other communication sheets by using capacitive coupling and the communication circuit of the communication sheet includes an LC circuit, the communication band becomes narrower and wide band communication becomes difficult.
Moreover, it is difficult to protect data confidentiality because the communication network formed by using capacitive coupling may leak electromagnetic waves or radio waves.